N-Butyl Cyanoacrylate-Lipiodol Mixture for Endovascular Purpose: Polymerization Kinetics Differences Between In Vitro and In Vivo Experiments

Endoscopic treatment of bleeding gastric ulcer causing gastric wall necrosis: A case report

BACKGROUND

Gastric wall necrosis is a rare complication of endoscopic treatment for bleeding gastric ulcer, which may exacerbate the patient's condition once it occurs and may even require surgical intervention for treatment.

CASE SUMMARY

A 59-year-old man was admitted to our department with melena. Endoscopy revealed a giant ulcer in the gastric antrum with a visible vessel in its center, which was treated with sclerosants and tissue glue injection and resulted in necrosis of the gastric wall.

CONCLUSION

Injection of sclerosants and tissue glue may lead to gastric wall necrosis, which is a serious complication. Therefore, before administering this treatment to patients, we should consider other more effective methods of hemostasis to avoid gastric wall necrosis.

Polymerisation of cyanoacrylates: The effect of sclero-embolic and contrast agents

OBJECTIVES

The objective is to investigate the interaction of sclero-embolic and contrast agents with the polymerisation of medical grade n-butyl-cyanoacrylates.

METHODS

An in vitro spectrophotometric absorbance method was developed to detect changes in light transmission to measure n-BCA polymerisation. The initiation and the rate-of-polymerisation of mixtures of n-BCA with sclero-embolic and contrast agents were investigated.

RESULTS

Initiation of polymerisation: VENABLOCK™ and HISTOACRYL® were the fastest agents to polymerise, while VENASEAL™ was the slowest. Rate of polymerisation: Hypertonic saline inhibited the polymerisation of all n-BCAs, while hypertonic glucose prolonged the polymerisation rate. ETHANOL and detergent sclerosants had no effect. Contrast agents OMNIPAQUE™ and ULTRAVIST® initiated and prolonged the polymerisation of n-BCA, but in contrast, LIPIODOL® failed to initiate the process.

CONCLUSIONS

The commercially available medical cyanoacrylates differ in their polymerisation rates. These polymerisation rates are further affected when these products are used in conjunction with other compounds, such as sclero-embolic and contrast agents.

X-ray Microtomography to Assess Determinants of In Vivo N-Butyl Cyanoacrylate Glubran®2 Polymerization: A Rabbit-Model Study

Although introduced decades ago, few cyanoacrylate glues have been approved for endovascular use, despite evidence of their usefulness, notably for complex procedures suchas hemostatic embolization. Indications include massive bleeding requiring emergent hemostasis and prevention of severe bleeding during scheduled surgery to remove a hypervascular tumor. Adding radiopaque Lipiodol Ultra Fluid® (LUF) modulates glue polymerization and allows fluoroscopic guidance, but few comparative in vivo studies have assessed the impact of the resulting change in glue concentration or of other factors such as target-vessel blood flow. In a rabbit model, we used ex vivo X-ray microtomography to assess the results of in vivo renal-artery embolization by various mixtures of N-butyl cyanoacrylate (NBCA), metacryloxysulfolane, and LUF. Overall, penetration to the superficial interlobular arteries was achieved in about two-thirds of cases and into the capillaries in nearly half the cases, while cast fragmentation was seen in slightly more than half the cases. Greater NBCA dilution and the blocked-blood-flow technique were independently associated with greater distality of penetration. Blocked-blood-flow injection was independently associated with absence of fragmentation, capillary penetration, a shorter cast-to-capsule distance, and higher cast attenuation. A larger mixture volume was independently associated with higher indexed cast ratio and deeper penetration. Finally, microtomography is an adapted tool to assess ex vivo distribution of glue cast.

Prostatic Artery Embolization for Benign Prostatic Obstruction: Single-Centre Retrospective Study Comparing Microspheres Versus n-Butyl Cyanoacrylate

PURPOSE

To compare the safety and efficacy of n-butyl cyanoacrylate glue (NBCA) versus microspheres for prostatic artery embolization (PAE) in patients with benign prostatic obstruction (BPO).

MATERIALS AND METHODS

This institutional review board-approved, single-centre, retrospective study included consecutive patients undergoing PAE from September 2017 to July 2020. Age, medical history, previous treatment, pre- and post-PAE prostatic volumes and International Prostate Symptom Scores (IPSSs) were systematically analysed. Procedural duration, dosimetry, immediate and delayed complications were recorded. Patients at the beginning of the study were treated with microspheres and patients at the end of the study with NBCA. The main outcome measures were the absolute and relative changes in IPSS at 3 months. Statistical analyses comprised unpaired t-tests, Wilcoxon tests, Chi-2 tests, uni- and multivariate linear regressions.

RESULTS

Sixty-two patients were included (median age: 65.9 years). Thirty-two patients were treated with microspheres and 30 with NBCA. There were no significant baseline differences between the two groups except for the baseline PSA (P = 0.0251). Average procedural and fluoroscopy times, and radiation exposure were significantly lower in the NBCA group versus the microspheres group (80.7 ± 22.5 versus 112 ± 42.1 min [P = 0.0011], 24.2 ± 9.6 min versus 42.1 ± 20.2 min [P = 0.0001], 12,004.6 ± 6702 uGy.m² versus 25,614.9 ± 15,749.2 uGy.m² [P = 0.0001], respectively). Immediate complications were all minor, and there were no significant differences between the two groups (4/32 [12.5%] with microspheres versus 7/30 [23.3%] with NBCA, P = 0.4335), nor for delayed complications (P = 1). No association was found between the PAE techniques and the absolute change in IPSS at 3 months (-10.2 ± 7.9 with microspheres versus -9.5 ± 7.6 with NBCA, P = 0.7157).

CONCLUSION

PAE using NBCA was safe and effective for symptomatic BPO, with faster procedures, lower radiation exposure and similar safety and efficacy compared to microspheres. Operator learning curve could have biased the procedural times and radiation exposure between groups favouring NBCA.

In Vivo Experimental Endovascular Uses of Cyanoacrylate in Non-Modified Arteries: A Systematic Review

Cyanoacrylates were first used for medical purposes during World War II to close skin wounds. Over time, medical applications were developed, specifically in the vascular field. Uses now range from extravascular instillation in vascular grafting to intravascular injection for embolization. These applications were made possible by the conduct of numerous preclinical studies involving a variety of tests and outcome measures, including angiographic and histological criteria. Cyanoacrylates were first harshly criticized by vascular surgeons, chiefly due to their fast and irreversible polymerization. Over the past five years, however, cyanoacrylates have earned an established place in endovascular interventional radiology. Given the irreversible effects of cyanoacrylates, studies in animal models are ethically acceptable only if supported by reliable preliminary data. Many animal studies of cyanoacrylates involved the experimental creation of aneurysms or arteriovenous fistulas, whose treatment by endovascular embolization was then assessed. In clinical practice, however, injection into non-modified arteries may be desirable, for instance, to deprive a tumor of its vascular supply. To help investigators in this field select the animal models and procedures that are most appropriate for their objectives, we have reviewed all published in vivo animal studies that involved the injection of cyanoacrylates into non-modified arteries to discuss their main characteristics and endpoints.